How to export metrics when they are created, and not every interval?

[meirtolpin11]

Hi,
I am trying to figure out how can I export metrics from python code using opentelemetry.
All the examples I see are using PeriodicExportingMetricReader. The issue is that I want to create a metric that will be reported once and the PeriodicExportingMetricReader is reporting each of my metrics every interval.

I tried to use Counters, Histogram and Gauge, but was unable to find a way to export a metric just once without repeating it's value each exporting interval.

Is it possible?

I want to collect metrics about when some function was called, so I need a separate "dot" on the graph for each time the function called, when the "y-axis" of the dot will be the time it took to execute the function (I calculate it manually). But I want to get it only once, without getting the same dot each exporting interval.

Maybe I am looking for something different then metrics, but I will appreciate any suggestion.

[ocelotl]

We do have an InMemoryMetricReader whose method get_metrics_data returns MetricsData that can be passed to the export method of an exporter. Maybe that works for you?

[sandipb]

Found this discussion while searching for the same thing.

One other option is the "hidden" feature implemented in #3059.

ie. create the PeriodicExportingMetricReader with an interval of Math.inf and retain the instance somewhere. And then whenever you want to emit, call the .collect() on it.
I haven't tested it out myself, but that pull request has tests for it which apparently passed :)